Effect of stocking density on growth performance and meat quality in Iberian pigs under extensive conditions

Intoduction The Iberian pig production system under the "cebo de campo" category allows for a wide range of stocking densities, potentially leading to variability in productive performance and meat quality. This study aimed to evaluate the effect of two contrasting stocking densities (15 vs 100 pigs/ha) on growth performance, feed efficiency, carcass traits, and meat quality in purebred Iberian pigs. Methods Twenty castrated male pigs were allocated to two treatments: low stocking density with access to pasture (LOW) and high stocking density without pasture access (HIGH) during a 74-day finishing period. Both groups received identical concentrate allowances. Result Pigs reared at high stocking density showed greater average daily gain (P = 0.049) and tended to have improved feed conversion ratio. These differences were mainly observed during the late fattening phase. Backfat thickness was higher in the HIGH group (P = 0.008), whereas no significant differences were detected in carcass yield or prime cuts. Meat quality traits, including colour, intramuscular fat, antioxidant content, and fatty acid profile, were largely unaffected by stocking density. Conclusion Overall, the results suggest that increased stocking density under outdoor conditions may improve productive performance without compromising meat quality, with differences primarily driven by variations in energy expenditure rather than pasture intake.